Nowadays, two-dimensional codes are widely used in daily life, and a billboard usually has a two-dimensional code on it for a function of further publicizing.
Traditionally, a two-dimensional code displayed on a billboard is always disposed at a certain location of the billboard (for example, the lower right corner). If the size of the two-dimensional code is small, a user needs to move a mobile device (for example, a smart phone, etc.) close to the billboard so that the two-dimensional code can occupy the entire scanning frame of the mobile device so as to scan a code, which is inconvenient for user operation. In particular, for a large billboard on a side of a road or on a hill, etc., a user cannot scan a two-dimensional code on the billboard with a mobile device because the user cannot approach the billboard. Therefore, a two-dimensional code on a traditional billboard of this kind will not work. However, if the area of a two-dimensional code is enlarged to a size that can be recognized at the normal viewing distance, valuable and effective advertisement area will be compromised inevitably.
In addition, a two-dimensional code on a billboard cannot act as an index means. As for an index means in other words it means that, in case, a user may hope to save the billboard together with the two-dimensional code contained thereon by taking a picture and storing an image, so as to allow others to obtain further information by scanning the two-dimensional code on the stored image. Since a traditional two-dimensional code occupies only a very small area of an image, the definition of the two-dimensional code image is low, and therefore it cannot be identified and thus cannot serve as an index.
Therefore, a billboard containing encoded information is required to address the above problem.